1. Field of the Invention
This invention relates to a slide valve for controlling the operation of a hydraulic actuator, such as a cylinder. More particularly, this invention relates to a slide valve with a speed limiting device for controlling the operation and the speed of operation of a hydraulic actuator such as a cylinder.
2. Description of the Prior Art
It is known to control the operation of a hydraulic actuator such as a cylinder by means of a slide valve which slides between two extreme positions as a result of a control pressure applied to one or another of its ends.
A slide valve as described may be used, for example, to apply an inlet pressure in one chamber of a cylinder whose other chamber is interconnected with the return tank. A hydraulic system using such a slide valve performs satisfactorily as long as the displacement of the piston of the cylinder occurs against a counter pressure. However, whenever the piston of the cylinder is not subjected to such a counter pressure, it is likely to operate faster than the speed set by the inflow, and this may cause a pressure drop upstream from the cylinder, due to the acceleration of the displacement of its piston.